Currently, the way for assembly a ceiling lamp is classified into a singe stage way and a multiple stage way. Since the tube of the lamp is installed with electric wires, for easily installing the tube, before sold, the lamp rod and the wire connecting box are connected so that the volume of the lamp is large and thus the cost is high. Thereby, there is an eager demand for a novel electric connecting structure for a lamp which can be assembled by the user himself (herself) so as to reduce the volume in package and reduce the cost in transfer.